With the development of medical technology, the extracorporeal shock wave lithotripter is used increasingly. In order to break up intracorporal calculus more thoroughly, the focus pressure of shock wave is designed to be higher and higher. However, it brings about that the pressure of the shock wave exceeds the tolerance limit of human soft tissues resulting in damages of human soft tissues. Therefore, the problem which is urgent to be solved is to provide an extracorporeal shock wave lithotripter which has little or almost no damage to human body.